Measuring the fabric evolution of sand – application and challenges

Abstract

The behaviour of granular materials, such as sands, is controlled by the interaction of particles. This interaction can be described geometrically by orientations and statically by forces. Using x‐ray μ‐tomography and image analysis, it is possible to determine the geometrical fabric at the grain‐scale, whereas the forces still remain inaccessible in natural granular materials. This article shows how the fabric can be accessed using standard and recently proposed advanced image analysis techniques and elaborates which problems arise when describing the fabric quantitatively. These techniques were applied to a triaxial compression test on Hostun sand. The results are described in terms of a fabric tensor, a coordination number and an anisotropy and then related to the macroscopic behaviour of the sample.